Regulating mechanism for turbo-mechanical-machine plants



O. A. WIBERG AND G. KARL-SSON. REGULATING MECHANISM FOR TURBO MECHANICALMACHINE PLANTS.

APPLICATION FILED MAY]. 1920.

Patented Aug. 16, 1921.

oscAR ANTON WI'BERG ,AND ,GEORG' 'KARLSSON, or rrnsrono, SWEDEN.

'REGULATING MECHANISM roe s.runeo mncnsmcannaenrnn- PLANTS.

Application filed May '7,

To all whom it may concern. 7 1

Be it known that we, OsoAR ANTON VVI- nnne and Gnono KAnLssoN, subjectsof the King of Sweden, whose post-office addresses are Finspong, Sweden,have invented new and useful Improvements in Regulating Mechanism forPlants, (for which we have'filed application in Sweden J an. 20, 1919),of which the following is a specification.

This invention relates to turbo-mechanical machine plants having amechanical reversing device controlled by a hand-wheel or the like. Insuch machine plants it has proved desirable to reduce the number ofrevolutions of the turbine while the reversal of the direction ofrotation of the driven shaft is taking place.

The object of the invention is to provide means whereby the number ofrevolutionsof the turbine is automaticall reduced, previous to saidreversal. To t is end the said hand-wheel is operatively connected to adevice for adjusting the s eed governor of the turbine in such a waythat upon turningthe hand-wheel to effect the reversal, an adjustment ofthe governor. for a reduced number of revolutions of the turbine willtake place.

I11 the accompanyingdrawing, a diagrammatical View of a regulatingmechanism according -to this invention is shown, certain parts of saidmechanism being shown .in section.

\Vith reference to the drawing, the character A indicatesthe-centrifugal governor of a turbo-mechanical machine plant, the.latter, however, "being not illustrated, as it does not form any partof this invention. .The character B indicates the steam inlet valve ofthe turbine, said inlet valve being con trolled by the governor A, andat C parts of a mechanical reversing device are shown. Said device'maybe mountedon the. driven shaft of the machine, plant or on any suitableintermediate shaft.

The centrifugal. governor shown is designed to operate at twoJdifierentnumbers of revolutions of the turbine, as for instance, at 8,000 and1,500 revolutions per minute, the. higher. number of revolutions corre-,sponding to the normalsspeed. of .the turbine. The governor. comprises arotary casing '1, in which are mounted two swinging weights 2 acted onby two coiled tension springs 3,4;

Turbo-Mechanical-Machine Specification of Letters Patent. 8 'P'atelltedAug, 16, 1921.

1920. Serial no, 379,613. 5

ofwhich the former is rigidly secured with its one end to the governorweights, while the corresponding end of the spring a is attached to adisk 5. Freely extending through said disk is .a reduced portion 6 of ahead of. a rod serving to only move the disk 5 in opposition totheaction of the spring a after the governor weights have made a certain.thro

The governor weights are connected by means of. a rod 7 to a slide-valve8 controlling the supply of pressure medium to the cylinder 9 of apiston motor serving to di rectly control the steam inlet valve 13. Thepressure medium is supplied from .a pump 10 through a conduit 11 leadingtothe stationary slide-valve casing 12 said casing being connected atits opposite side to the cylinder 9 by means ofthe conduit 13. The

cylinder 9 contains a piston 14 the rod 15 of which carries, the movablesteam inlet valve body 16. On the side of the piston 14 opposite to theconduit 13, the casing 9 contains a I pressure springl'r' acting onsaidpiston. v

Toadjust the governor for different numbers of revolutions and to adjustthe slide valve 8, 12 after each movement of the steam inlet valve, thefollowing arrangement is provided. Inserted between the stationary slidevalve casing 12-and the slide valve 8 is a movable slide valve casing 18having three chambers communicating with the, conduit 11, the conduit'13 and a discharge conduit (not shown), respectively, the communicationwith said discharge conduit being effected by. openings 19. The slidevalve casing. 18 is connected through a link 20 to one arm of a rockinglever 21, the other arm of which is connected bymeans of a link 22 toone end of a shifting lever 23, pivotally connected as at 24 to the rod25 of the piston 27 of a shift control motor. The other end of theshiftinglever 23 is connected to the piston rod15 carrying the steaminlet valve 16. The piston 27 of the shiftlcontrol motor is adapted tomove in the one direction under the action of a spring 28 and in theother direction under the action of a pressure medium supplied by thepump 10. I he communication between the pump 10 and the cylinder 27comprises a conduit 30 having a return valve 29, a branch conduit 31extending from said'conoluit'30, a controlling mechanism including astationary slide valve casing 32 and a slide-valve 33, and a connectlngconduit 34 between the slide-valve casing 32 and the cylinder 26. Theslide-valve 33 is pivotally connected as n han d-wheel 39 of the turbinemachineplant.

7 piston Said shaft also carries a gear wheel 40 engaging a rack 41 bymeans of which the reversing mechanism C may be controlled from thehand-wheel 39.

The reversing mechanism is only shown partially, as the constructionthereof has nothing to do with this invention. The reversing mechanismcomprises two lamination friction couplings, that is, one ahead coupling42 and one back coupling 43, a set of hydraulic pistons44, a piston 45connected to said pistons 44 and acting directly on'the back couplingdisks 43, and. a link system 46, by means of which the disks of theahead coupling 42 may be operated from the piston 45. The pistons 44(one of which only is shown in the drawing) are operated by means of apressure medium supplied from the conduit 30 under the control of. aslidevalve 47, in turn controlled by the pistons 44 and the hand-wheel39, the slide-valve 47 being connected to one of the pistons 44 by meansof a lever 48 also connected to the rack 41. Leading to the backcoupling disks 43 is a lubricating conduit 49 controlled by a.

valve 50 operated by a pressure medium under the control of the slidevalve 47. Assuming the pressure medium consists of oil, the valve 50controls the connection between the conduit 49 and a branch 51 of theconduit 30. 4

The operation of the system described is as follows: In the position ofthe parts of the system shown in the drawing, the reversing mechanism Cand thus also the driven shaft are assumed to be released and themachine plant is assumed to operate with reduced speed. If it is desiredto throw the driven shaft into action for operation at a certain speedahead, the hand wheel 39 is turned in the direction of the arrow a. Therack 41 is thereby moved to the left thus moving the slide valve 47 tothe left so as to connect the conduit 30 with the left-hand side of thepistons 44, thereby causing the pistons 44 to move to the right. Throughthe link system 46 the piston 45 operates the friction clutch 42 so asto throw in the same partially. In the movement of the piston 44 .to theright, said piston will turn the lever 48 so as to cause the same toagain move the slide valve 47 to the right. When the valve piston 44 inthis movement again reaches the central position shown in the drawing,the oil supply to the pistons 44 is cut ed. Upon further movement of thehand-wheel, the operation described again takes place and the coupling42 will thus be thrown in successively according as the hand-wheel isturned. Only after the pistons 44 reach their extreme right position,the slide valve 47 will open completely to permit pressure oil tooperate the pistons to throw in the coupling 42 completely and maintainit in operative position. This will take place when the hand-wheel 39 isturned to such an extent as to bring the connecting rod 37 into theposition I. The driven shaft is now thrown in for ahead operation androtates'with the above said reduced speed.

During the said turning of the hand-wheel, the valve 50 has beenkeptoclosed under the action of the pressure oil.

The hand-wheel, when turned into said position, has moved the lever 36so as to dcpress the slide valve 33. During the whole movement, however,the connection between the conduits 31 and 34 has been cut off at theslide-valve 33, and said slide valve is ready to restore saidconnectionat the completion of said movement. Thus, if the hand-wheel 39 is movedfarther in the direction above referred to, pressure oilwill enter thecylinder 26 below the piston 27 and raise the latter against the actionof the spring 28. The lever 36 is then caused to turn about itsconnection with the connecting rod 37 and will thus raise the slidevalve 33 so that the latter will again out off the connection betweenthe conduits 31 and 34. The length ofthe movement of the piston 27depends on the rotation of the hand wheel 39 beyond the position thereofcorresponding to the position I of the connecting rod 37.

In the said movement of the piston 27, the lever 23 is also turned aboutits connection with the piston rod 15, the link 22 being thereby raisedand the movable slidevalve casing19 lowered so as to interconnect theconduit 11 and the conduit 13 to permit pressure oil to enter thecylinder 9 below the piston 14. Said piston will thus be raised to openthe steam inlet valve 16 by means of the rod 15 to increase the speed,of the turbine. lVhen the rod 15 is thus m ved upwardly, the lever 24swings back and the movable slide-valve casing 19 is moved upwardly soas to again out off the connection between the conduits11 and 13. Thesteam inlet valve will remain in its position and the turbine willoperate with a speed corresponding to the opening of the steam inlet.The magnitude of the opening of the steam inlet depends on the movementof the piston 27 and said movement, in turn, depends on the rotation ofthe hand- Wheel 39. A continued rotation of the handwheel in thedirection indicated will further open the steam inlet valve and it isthus possible to manually control the speed of the turbine by means ofthe hand-wheel.

The manual control above described is possible with respect to turbinespeeds between the values for which the governor is designed to operate,that is in this case for speeds lying between 3,000 and 1,500revolutions per minute. As soon as the speed of the turbine in themanual control exceeds such values, the governor begins to operate andwill control the steam inlet valve by means of the slide valve 8 in wellknown manner.

When the movement of the driven shaft is to be'rev'ersed, the hand-wheelis turned back out of theposition, into which it has been moved in theincrease of the speed above described. In this movement, the connectingrod 37 is moved upward and the slide valve 33 is raised to out ofi theconnection between the conduits 31 and 34-and to further connect theconduit 34 to an outlet 52., The spring 28 is now free to depress thepiston 27 thereby causing the slide-valve 33 to close the outlet 52 andraising the movable slide-valve casing 19 so as to bring the cylinderchamber below the piston 14 in communication with an outlet through theopenings 19. The spring 17 is now free to depress the piston 14 to closethe inlet valve 16. As in the increase of the speed, the closing of theinlet valve 16 takes place successlvely according as the hand-wheel isturned back.

In the turning back of the hand-wheel,

' the rack 41 is moved to the right to operate the slide-valve 47 so asto permit pressure oil to act upon the right-hand side of the pistons44, while the pressure oil to the left of said pistons is allowed toescape. At the same time, the pressure oil is drawn off from theright-hand side of the piston valve 50 thereby allowing the latter,under the action of its spring, to interconnect the conduits 51 and 49for the purpose mentioned below. In the same way as the movement of thepistons 44 to the right, previously described, the movement of thepistons 44 to the left will take place successively. The hand-wheelhaving againreached the neutral position shown in the drawing, the

' pistons 44 are again moved to their central position in which theywill maintain both the couplings 42 and 43 released. The driven shaft,therefore, will now be at rest. At the same time, the steam-inlet 16 isclosed to such an extent that the speed of the turbine is reduced to thelower one of the two speeds for which the governor can operate. Thegovernor will thus be set into operation to maintain the turbine at saidreduced speed.

If the hand-wheel is turned beyond the neutral position, the rack 41continues to move to the right, the pistons 44 being there- During therotation of the hand-wheel I into the position, corresponding to theposition II of the connecting rod 37, the slide valve 33 is so operatedas to be ready to interconnect the conduits 31 and 34 at the completionof .said rotation. In the continued rotation of the hand-wheel, saidconnection will thus take place and the piston 27 of the reversing motorwill be set into operation in the same way as above describechtoinitiate the opening of the steam inletvalve 16 which will then beopened gradually according as the hand-Wheel is rotated therebyincreasing the speed of the turbine, while the governor still remainsout of action. hen the speed of the turbine reaches the highest value,for which the governor is designed, the governor will again commence itsaction.

During all the time that the back coupling 43 is in action, pressure oilmay be freely supplied to the disks of said coupling through theconduits 51, 49. This oil supply has for its object to consume the heatgenerated due to the friction which occurs when the coupling is throwninto action.

From the above description it will be seen that the operation of thereversing mechanism will always take place at a reduced speed of theturbine which will secure a soft and quiet reversal.

It should also be noted that the reduction of the speed of the turbineand the reversal of the turbine are effected by means of one and thesame hand-wheel the speed reduction leading in respect to the reversal,the said hand-wheel also enabling a manual speed control of the machinein the range lying between the two speeds for which the governorisdesigned to operate. Only in the event of areduction of the speed belowthe lowest value for which the governormay operate, an adjustment of thesteam in let by means other than the said handwheel is necessary.

Having now described our said invention we declare that what we claimis 1. Regulating mechanism for turbo mechanical machine plants,comprising in combination amechanical reversing device, a hand-wheel forcontrolling said reversing device, a turbine speed governor, aconnection between said hand-wheel and said speed governor sodesignedthat in turning the hand wheel for effecting a reversal an adjustment ofthe governor to operate for a distinct reduced speed will take placeprevious to the said reversal.

2. Regulating mechanism for turbomechanical machine plants, comprisingin combination a turbine speed governor, a hydraulic piston foradjusting said governor to operate for two diiierent speeds, ahand-wheel for controlling the operation of said piston, a reversingdevice, hydraulic pistons for operating said reversing device,slide-valves for controlling the admission of pressure medium to saidlast-mentioned pistons, and a connection between said hand-wheel andsaid last-mentioned pistons so designed that in turning the handwheel,the reversing device is operated after the operation of the pistoncontrolling the governor.

3. Regulating mechanism for turbomechanical machine plants, comprisingin combination a speed governor, means for adjusting said governor tooperate for different speeds, a reversing device, means for controllingsaid reversing device, a handwheel so connected with said means as tohold the reversing device out of action when in a neutral position andto operate the means for adjusting the governor, when moving within acertain range on each side of said neutral position, while operating themeans for controlling the reversing device when moving outside of saidrange.

4:. Regulating mechanism for turbomechanical machine plants, comprisingin combination a speed governor, a handwheel controlling said speedgovernor, a reversing device, including a laminated friction couplingfor ahead motion and a laminated friction coupling for back motion, anoil supply to said back coupling, said oil supply being controlled bysaid hand-wheel.

In testimony whereof we have signed our names.

OSCAR ANTON WIBERG. snone KARLSSON.

